The proposed clinical trials unit is located at Universidade Federal do Rio de Janeiro (UFRJ), in Rio de Janeiro, Brazil, and includes only one clinical research site, which is called Projeto Praqa Onze. We propose to affiliate with the HIV Vaccine Trials Network (HVTN) and with the Adult AIDS Clinical Trials Group (ACTG). Our site was listed in the HVTN Leadership application. We have over 10 years of experience in conducting NIH-sponsored studies of HIV infection. Thus, the necessary facilities as well as regulatory, administrative and fiscal structures are already in place, including a Federal-wide assurance approval and a fully functioning Institutional Review Board that meets U.S. government requirements. We have documented access to the populations needed for the conduct of the research agenda proposed by both the HVTN and the ACTG leadership applications. We have documented capability to conduct rigorous randomized therapeutic clinical trials according to Good Clinical Practice standards. We have the necessary facilities to collect, process, store, and ship to appropriate central laboratories blood, body fluids, and tissue samples obtained from clinical trial participants. Additionally, we have considerable experience in the simultaneous conduct of multiple studies involving several hundred participants. We also have a documented track record of recruiting, screening, enrolling, and following research participants with very low attrition rates in all high-priority research areas in which we propose to take part. The organization of the site promotes synergy between the various research areas, favoring the optimal use of available resources. Most importantly, the site has strong community support. Finally, we have the necessary expertise to participate in the development of the scientific agenda of both networks, as well as the capacity to effectively contribute to the design and conduct of trials needed to meet the scientific agenda of both networks. ADMINISTRATIVE COMPONENT: